[gān xīn]
(愿意) willingly; readily
He did it quite willingly.
他甘心做这事。
They couldn't be reconciled to such a prospect.
他们不能甘心于这样一个前景。
They will certainly not resign themselves to be slaves.
他们肯定不会甘心受人奴役。
They didn't take their defeat lying down.
他们不甘心失败。